Lawn mower
By incorporating a guide zone, feeding zone, and discharge zone into the lawnmower, combined with a cutting aid and elastic components, the problem of difficult grass collection in lawnmowers has been solved, achieving efficient grass cutting and collection, and making it suitable for lawn mowing at different heights.
Patent Information
- Application Number
- CN202423216228.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Existing lawn mowers often result in broken grass that is difficult to collect during the cutting process, especially for shorter grass, and they are prone to spilling broken grass.
A lawnmower was designed, which uses a guide plate and a positioning plate to form a guide zone, a feeding zone and a discharge zone. Combined with a cutting auxiliary device and an elastic element, the lawn is cut by the contact between the roller blade and the cutting auxiliary device, and the lawn is collected smoothly by the reset of the elastic element to avoid spillage.
It achieves efficient cutting and collection of grass, reduces the risk of broken grass spillage, and is suitable for lawn mowing at different heights.
Smart Images
Figure CN223714614U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of lawn mowing equipment, and more particularly to a lawn mower. Background Technology
[0002] A lawnmower is a fully automated mechanical tool used for trimming lawns and vegetation. It is widely used in garden decoration trimming, home and public lawn greening trimming and other occasions.
[0003] Existing lawnmowers such as Figure 1 As shown, the device includes a roller cutter device 1, wherein the roller cutter 101 on the roller cutter device 1 pushes the grass onto the guide plate 102 at the feed inlet 100 position, and cuts the grass by utilizing the gap between the roller cutter 101 and the guide plate 102. Then the roller cutter 101 continues to push the cut grass backward and flows out from the discharge outlet 1000, and finally collects the cut grass.
[0004] like Figure 1 As shown, the feed inlet 100 is located directly below the rotating shaft 103 of the roller cutter device 1. The guide plate 102 stops at the feed inlet 100 to facilitate the grass being directly pushed into the gap between the guide plate 102 and the roller cutter 101. Since the roller cutter 101 is positioned by the positioning plate 104, when the grass continues to be pushed upward after passing the discharge port 1000, the broken grass will continue to rise to the highest point and then fall downward. At this time, the fallen grass will fall near the feed inlet 100, causing the broken grass to flow out of the guide plate 102, making it difficult to collect the broken grass. If the guide plate 102 extends forward along the horizontal plane, as shown by the dotted line, then the grass is not easily pushed into the gap between the guide plate 102 and the roller cutter 101. At this time, it is more difficult to cut the grass, and the mower can only be used to cut longer grass, but cannot cut shorter grass. Utility Model Content
[0005] This application provides a lawnmower that solves the technical problem of inconvenient collection of broken grass during the cutting process of existing rotary cutting devices.
[0006] According to a first aspect of this application, a lawnmower is provided, including a rotary blade assembly and a drive mechanism for providing power to the rotary blade assembly. The rotary blade assembly includes a plurality of rotary blades, a guide plate, a rotating shaft, and a plurality of positioning discs, wherein the plurality of positioning discs are distributed along the axial direction of the rotating shaft and are fixedly connected to the rotating shaft.
[0007] Several hobbing cutters are distributed along the circumference of the positioning disk and fixed on the peripheral wall of the positioning disk;
[0008] The guide plate is located on one side of the rotating shaft and forms a gap with the peripheral wall of the positioning disk for grass flow;
[0009] The ports of the area formed by the guide plate and the positioning plate are the inlet and the outlet, respectively. Between the inlet and the outlet, there are sequentially a feeding area, a dropping area and a guide area.
[0010] A cutting aid device is rotatably installed in the feeding area, and the cutting aid device abuts against one of the roller cutter blades to assist in cutting the grass;
[0011] An elastic element is installed between the guide plate and the cutting auxiliary device to tilt the cutting auxiliary device at an angle so that the cutting auxiliary device can contact the cutting blade.
[0012] In one embodiment, the cutting auxiliary device includes a cutting plate and a first rotating shaft. The cutting plate is inclined and forms an angle with the horizontal plane. The first rotating shaft is arranged along the axial direction of the rotating shaft and is fixedly mounted on the cutting plate. The first rotating shaft is rotatably connected to the guide plate.
[0013] In one embodiment, the elastic element includes elastic rubber, which is fixedly installed between the guide plate and the cutting plate.
[0014] In one embodiment, the elastic element includes a torsion spring, which is sleeved on the first rotating shaft. One end of the torsion spring is fixedly connected to the first rotating shaft, and the other end of the torsion spring is fixedly connected to the guide plate.
[0015] In one embodiment, a material discharge baffle is also included. One side of the material discharge baffle is rotatably connected to the cutting plate via a second rotating shaft, and the other side of the material discharge baffle is slidably connected to the top wall of the guide plate. The longitudinal sections of the material discharge baffle and the cutting plate are in the shape of a "V".
[0016] In one embodiment, the device further includes a frame, a chassis, and a lifting assembly. The roller cutter device and the drive mechanism are mounted on the frame, and the frame is mounted on the chassis via the lifting assembly to enable the roller cutter device to rise or fall as a whole.
[0017] In one embodiment, the device also includes a material collection bin, which is fixedly mounted on the vehicle frame. The material collection bin has a feed window, and the discharge port of the roller cutter extends through the feed window into the inner cavity of the material collection bin.
[0018] In one embodiment, the discharge port includes a guide bottom plate, a guide side plate, and a baffle plate. The guide bottom plate is fixedly installed on the guide plate and is horizontally arranged. The guide plate extends through the feed window into the inner cavity of the collection bin. The guide side plate is fixedly installed on the guide bottom plate and extends vertically upward. The baffle plate is rotatably installed on the bottom wall of the guide bottom plate and hangs down into the inner cavity of the collection bin. When the frame is raised, the baffle plate blocks the feed window below the guide bottom plate to prevent the flow of broken grass.
[0019] In an embodiment, the guide rail is fixedly installed on the frame and arranged vertically, and the sliding groove is arranged on the vehicle frame and in sliding connection with the guide rail.
[0020] In an embodiment, the lifting assembly comprises an electric push rod, a body of the electric push rod is fixedly installed on the vehicle frame, and a top end of the electric push rod is connected with the frame.
[0021] Compared with the prior art, the mower has the following beneficial effects:
[0022] The guide plate forms a falling area and a feeding area along the horizontal direction at the feeding port, the guide plate and the positioning disc form a guide area, a cutting auxiliary device is arranged at the feeding area, when the driving mechanism provides power for the rolling cutter device, the rolling cutter rotates clockwise to push the grass to the feeding area, at this time, the cutting edge of the rolling cutter abuts against the cutting auxiliary device and applies a pushing force to the cutting auxiliary device, so that the grass is cut off, at this time, the elastic member is deformed, when the rolling cutter passes the cutting auxiliary device, the cut grass is pushed to the guide area, the cutting auxiliary device is reset under the action of the elastic member to be in contact with the next rolling cutter, the rolling cutter then pushes the grass to the discharge port for collection of the cut grass, if the grass passes the discharge port to the highest point and then falls down, at this time, the grass falls into the falling area, because the elastic member pushes the cutting auxiliary device to form an included angle, so that the grass falling into the falling area cannot fall back to the ground through the feeding area, with the rotation of the rolling cutter, the cut grass is re-pushed to move along the guide area until the collection work of the cut grass is completed.
[0023] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS
[0024] The above and other objects, features and advantages of the example embodiments of the present application will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0025] In the drawings, identical or corresponding reference signs refer to identical or corresponding parts.
[0026] Figure 1 A schematic view of a prior art structure is shown;
[0027] Figure 2 A schematic view of the overall structure of the present application is shown;
[0028] Figure 3 A sectional view of the present application is shown;
[0029] Figure 4 A sectional view of the present application is shown; Figure 3a local enlarged structural schematic view of the cutting device;
[0030] Figure 5 a structural schematic view of the cutting device is shown;
[0031] Figure 6 a local sectional view of the cutting device is shown;
[0032] Figure 7 a structural schematic view of the cutting device is shown.
[0033] Explanation of figure numbers:
[0034] 1. cutting device; 100, feeding inlet; 1000, discharging outlet; 101, cutting knife; 102, guide plate; 103, rotating shaft; 104, positioning disc;
[0035] 11. feeding area; 12, blanking area; 13, guide area;
[0036] 2. driving mechanism; 21, motor; 22, pulley set;
[0037] 3. blanking auxiliary device; 31, blanking plate; 32, first rotating shaft;
[0038] 4. elastic member;
[0039] 5. blanking baffle; 51, second rotating shaft;
[0040] 6. elastic baffle;
[0041] 7. frame; 71, guide rail; 72, sliding groove; 73, electric push rod;
[0042] 8. vehicle frame;
[0043] 9. material collecting bin; 91, feeding window;
[0044] 1001, guide side plate; 1002, guide bottom plate; 1003, shielding plate. DETAILED DESCRIPTION
[0045] In order to make the purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0046] As Figure 1As shown, the mower includes a frame 8 and a material collecting bin 9 fixedly installed on the frame 8, a rotary cutter device 1 for cutting grass and a driving mechanism 2 for driving the rotary cutter device 1 are installed on a front portion of the frame 8, and Figure 4 As shown, the rotary cutter device 1 includes an inlet 100 and an outlet 1000, the grass enters the rotary cutter device 1 through the inlet 100 to be cut, and then flows into the material collecting bin 9 through the outlet 1000 to be collected.
[0047] As shown, Figure 3 The material collecting bin 9 is provided with an inlet window 91 close to the rotary cutter device 1, and the outlet 1000 of the rotary cutter device 1 extends into the inner cavity of the material collecting bin 9 through the inlet window 91, so that the cut grass of the rotary cutter device 1 can be accurately discharged into the material collecting bin 9.
[0048] Specifically, the mower further includes a frame 7, wherein the rotary cutter device 1 and the driving mechanism 2 are installed on the frame 7, as shown, Figure 5 The frame 7 is installed on the frame 8 through a lifting assembly, and the rotary cutter device 1 can be lifted or lowered, so that the rotary cutter device 1 can cut the grass at different heights.
[0049] As shown, Figure 5 The lifting assembly includes an electric push rod 73, wherein the body of the electric push rod 73 is fixedly installed on the frame 8, and the top end of the electric push rod 73 is installed on the frame 7, so that the relative position between the frame 7 and the frame 8 can be adjusted through the electric push rod 73, thereby adjusting the distance between the rotary cutter device 1 and the ground, so that the rotary cutter device 1 can cut the grass at different heights.
[0050] When the frame 7 is pushed upward, the outlet 1000 is also lifted, the gap between the bottom wall of the outlet 1000 and the bottom wall of the inlet window 91 is increased, and the cut grass collected in the material collecting bin 9 can flow out from the gap between the inlet window 91 and the outlet 1000, causing the cut grass to fall on the lawn. Therefore, in the embodiment, as shown, Figure 3 and Figure 5 The mower further includes a shielding plate 1003, wherein the shielding plate 1003 is rotatably installed at the outlet 1000 of the rotary cutter device 1 and falls into the inner cavity of the material collecting bin 9 through the inlet window 91, and the shielding plate 1003 shields the inlet window 91 below the outlet 1000, thereby preventing the cut grass in the material collecting bin 9 from flowing out.
[0051] In order to compensate for the gap between the rotary cutter device 1 and the material collecting bin 9 and smoothly guide the cut grass at the outlet 1000 into the material collecting bin 9, in the embodiment, as shown, Figure 5As shown, it also includes a flow guide bottom plate 1002 and a flow guide side plate 1001. The flow guide bottom plate 1002 is horizontally arranged and extends through the feed window 91 into the inner cavity of the collection bin 9. There are two flow guide side plates 1001. The flow guide side plates 1001 are fixedly installed on the top wall of the flow guide bottom plate 1002 and extend vertically upward to prevent broken grass at the discharge port 1000 from overflowing from the side.
[0052] Specifically, the baffle plate 1003 is rotatably mounted on the bottom wall of the guide plate 1002.
[0053] In order to ensure the stable raising and lowering of the frame 7, in this embodiment, as follows: Figure 5 As shown, it also includes a guide rail 71 and a slide 72. The guide rail 71 is vertically arranged and fixedly installed on the frame 7, and the slide 72 is arranged on the frame 8. The guide rail 71 is inserted into the slide 72 and forms a sliding connection with the inner wall of the slide 72, thereby ensuring the stable lifting and lowering of the frame 7.
[0054] like Figure 4 As shown, the roller cutter device 1 includes several roller cutters 101, a rotating shaft 103, a guide plate 102, and several positioning discs 104. The positioning discs 104 are distributed along the axial direction of the rotating shaft 103 and are fixedly connected to the rotating shaft 103. The roller cutters 101 are placed along the axial direction of the rotating shaft 103 and are evenly distributed around the circumference of the positioning discs 104. The roller cutters 101 are fixedly installed on the peripheral wall of the positioning discs 104. The guide plate 102 is located on one side of the rotating shaft 103, and the guide plate 102 and the peripheral wall of the positioning discs 104 form a gap for the flow of cut grass.
[0055] In existing technologies, in order to cut the grass as quickly as possible, such as... Figure 1 As shown, the feed inlet 100 is located directly below the rotating shaft 103. At this time, the gap between the cutting edge of the hob 101 and the guide plate 102 is the smallest. In the prior art, the longitudinal section of the guide plate 102 is a quarter-fan shape and surrounds the outside of the positioning plate 104. The outlet at the other end of the guide plate 102 is the discharge port 1000.
[0056] In existing technologies, such as Figure 1 As shown, the area between the inlet 100 and the outlet 1000 is the guide zone 13. The grass is directly cut at the inlet 100 and then moved along the guide zone 13 to the outlet 1000 to realize the conveying of the cut grass.
[0057] Since the roller cutter 101 is fixed by the positioning plate 104, when the broken grass continues to rise after passing the discharge port 1000, the broken grass falls downward along a parabola at its highest point. The parabola here is as follows: Figure 1 As shown by the dotted line, the fallen grass can extend 100 mm beyond the feed inlet and fall to the ground, with broken grass scattered, making it difficult to collect.
[0058] As Figure 1 shown, if the bottom of the deflector 102 is extended forward along the horizontal direction, and the receiving of the forage is achieved by the extended dashed line, it is more difficult for the reamer 101 to move the grass into the gap between the reamer 101 and the deflector 102, and the cutting effect of the grass is poor, which is not conducive to the shearing of the grass.
[0059] Therefore, in the present embodiment, as Figure 4 shown, the deflector 102 is extended forward along the horizontal direction to form the material falling area 12 and the material feeding area 11. Specifically, the deflection area 13 is located in the gap between the deflector 102 and the peripheral wall of the positioning disc 104, and the feeding port 100 moves forward. At this time, from the feeding port 100 to the discharging port 1000, the three areas are in turn the material feeding area 11, the material falling area 12, and the deflection area 13.
[0060] In order to solve the problem of grass shearing effect, in the present embodiment, as Figure 4 shown, a cutting auxiliary device 3 is rotatably connected at the material feeding area 11. The cutting auxiliary device 3 is rotatably connected with the deflector 102, and an elastic member 4 is arranged between the cutting auxiliary device 3 and the deflector 102. The elastic member 4 maintains an inclined angle of the cutting auxiliary device 3, so that the cutting auxiliary device 3 is in contact with the cutting edge of the reamer 101, thereby cutting the grass.
[0061] Specifically, as Figure 7 shown, the cutting auxiliary device 3 includes a cutting plate 31 and a first rotating shaft 32. The first rotating shaft 32 is arranged along the axial direction of the rotating shaft 103, and is fixedly installed on one side of the cutting plate 31. The first rotating shaft 32 is rotatably connected with the deflector 102.
[0062] In an embodiment, the elastic member 4 is an elastic rubber, which is fixedly installed between the deflector 102 and the cutting plate 31. The cutting plate 31 abuts against the elastic rubber, so that the position of the cutting plate 31 away from the side of the first rotating shaft 32 points to the discharging port 1000. Under the driving of the driving mechanism 2, the cutting edge of one of the reamers 101 abuts against the inclined cutting plate 31. At this time, the reamer 101 applies a pressure to the cutting plate 31, thereby cutting the grass. At the same time, the cutting plate 31 forces the elastic rubber to be squeezed and deformed. When the reamer 101 passes through the cutting plate 31, the reamer 101 moves the cut grass through the deflection area 13 to the discharging port 1000. At this time, the cutting plate 31 is reset under the elastic force of the elastic rubber, so that the cutting plate 31 is in contact with the next reamer 101 to achieve the cutting operation of the next batch of grass.
[0063] In another embodiment, the elastic member 4 includes a torsional spring. The torsional spring is sleeved on the first rotating shaft 32, one end of the torsional spring is fixedly connected with the first rotating shaft 32, and the other end of the torsional spring is fixedly connected with the deflector 102.
[0064] When the cut grass continues to rise over the discharge port 1000, when the grass falls down at the highest point, the cut grass will fall into the discharge area 12, and the angle formed by the cutting plate 31 will prevent the cut grass from leaking out of the inlet 100. The grass that passes over the cutting plate 31 will pass through the discharge area 12 to re-stir the cut grass to flow through the guide area 13 and then move to the discharge port 1000, achieving the recycling collection of cut grass and reducing the risk of cut grass falling outside the mower.
[0065] In order to avoid the cut grass remaining in the gap between the cutting plate 31 and the guide plate 102, a discharge baffle 5 is also included, wherein the discharge baffle 5 is rotatably connected to the cutting plate 31 by a second rotating shaft 51, and the other side of the discharge baffle 5 is slidably connected to the guide plate 102, as shown in Figure 4 The longitudinal section of the discharge baffle 5 and the cutting plate 31 is in the shape of a "person", which can prevent the cut grass from entering the gap between the cutting plate 31 and the guide plate 102 when the grass falls into the discharge area 12.
[0066] Since the cutting plate 31 is rotatably connected to the guide plate 102 by the first rotating shaft 32, there is a gap at the connection between the cutting plate 31 and the guide plate 102, and the grass is easy to insert into this gap, thereby affecting the overturning of the cutting plate 31. Therefore, in this embodiment, as shown in Figure 3 and Figure 6 A resilient baffle 6 is also included, which is fixed on the guide plate 102, wherein the resilient baffle 6 is made of rubber material and is lapped on the surface of the cutting plate 31, which shields the gap at the connection between the cutting plate 31 and the guide plate 102 to prevent the insertion of grass, thereby solving the problem of the cutting plate 31 being stuck.
[0067] Specifically, as shown in Figure 5 The drive mechanism 2 includes a motor 21 and a pulley set 22, the motor 21 is fixedly installed on the frame 7, one of the pulleys of the pulley set 22 is connected to the output shaft of the motor 21, the other pulley of the pulley set 22 is connected to the rotating shaft 103, and the two pulleys are connected by a transmission belt to transmit power to the rotating shaft 103, thereby rotating the hob 101 and cutting the grass.
[0068] It should be understood that various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in the present application can be achieved, which are not limited herein.
[0069] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.
[0070] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A mower comprising a rolling cutter device (1) and a driving mechanism (2) for providing power to the rolling cutter device (1), the rolling cutter device (1) comprising a plurality of rolling cutters (101), a deflector (102), a rotating shaft (103) and a plurality of positioning discs (104), characterized in that, A plurality of positioning discs (104) are distributed along the axial direction of the rotating shaft (103) and fixedly connected with the rotating shaft (103); A plurality of hobbing cutters (101) are distributed along the circumferential direction of the positioning disc (104) and fixedly connected with the circumferential wall of the positioning disc (104); The guide plate (102) is located on one side of the rotating shaft (103) and forms a gap with the circumferential wall of the positioning disc (104) for the flow of grass; The ports formed by the guide plate (102) and the positioning disc (104) are respectively the feeding port (100) and the discharging port (1000), and the feeding port (100) to the discharging port (1000) are sequentially provided with a feeding area (11), a material falling area (12) and a guide area (13); The cutting auxiliary device (3) is rotatably installed in the feeding area (11), and the cutting auxiliary device (3) abuts against the cutting edge of one of the hobbing cutters (101) to assist the cutting of the grass; The elastic member (4) is installed between the guide plate (102) and the cutting auxiliary device (3) to tilt the cutting auxiliary device (3) by an angle so that the cutting auxiliary device (3) is in contact with the cutting edge of the hobbing cutter (101).
2. A lawnmower according to claim 1, characterised in that The cutting auxiliary device (3) comprises a cutting plate (31) and a first rotating shaft (32), the cutting plate (31) is obliquely arranged and forms an angle with the horizontal plane, the first rotating shaft (32) is arranged along the axial direction of the rotating shaft (103), the rotating shaft (103) is fixedly installed on the cutting plate (31), and the first rotating shaft (32) is rotatably connected with the guide plate (102).
3. A lawnmower according to claim 2, characterised in that The elastic member (4) comprises elastic rubber, which is fixedly installed between the guide plate (102) and the cutting plate (31).
4. A lawnmower according to claim 2, wherein, The elastic member (4) comprises a torsional spring, the torsional spring is sleeved on the first rotating shaft (32), one end of the torsional spring is fixedly connected with the first rotating shaft (32), and the other end of the torsional spring is fixedly connected with the guide plate (102).
5. A lawnmower according to claim 2, wherein, The material falling baffle (5) is rotatably connected with the cutting plate (31) on one side through a second rotating shaft (51), and is slidably connected with the top wall of the guide plate (102) on the other side; the longitudinal section of the material falling baffle (5) and the cutting plate (31) is in the shape of a "human” figure.
6. A lawnmower according to claim 1, characterised in that The frame (8) and the lifting assembly are further included, the hobbing cutter device (1) and the driving mechanism (2) are installed on the frame (7), and the frame (7) is installed on the frame (8) through the lifting assembly to realize the overall lifting or lowering of the hobbing cutter device (1).
7. A lawnmower according to claim 6, wherein, The material collecting bin (9) is fixedly installed on the frame (8), the material collecting bin (9) is provided with a feeding window (91), and the discharging port (1000) of the hobbing cutter device (1) extends into the inner cavity of the material collecting bin (9) through the feeding window (91).
8. A lawnmower according to claim 7, characterised in that The discharge port (1000) comprises a guide bottom plate (1002), a guide side plate (1001) and a shielding plate (1003). The guide bottom plate (1002) is fixedly installed on the guide plate (102) and horizontally arranged. The guide plate (102) extends through the feeding window (91) into the inner cavity of the material collecting bin (9). The guide side plate (1001) is fixedly installed on the guide bottom plate (1002) and vertically extends upward. The shielding plate (1003) is rotatably installed on the bottom wall of the guide bottom plate (1002) and falls into the inner cavity of the material collecting bin (9). When the frame (7) is raised, the shielding plate (1003) shields the feeding window (91) below the guide bottom plate (1002) to prevent the broken grass from flowing out.
9. A lawnmower according to claim 6, wherein, The lifting assembly comprises a guide rail (71) and a sliding groove (72). The guide rail (71) is fixedly installed on the frame (7) and vertically arranged. The sliding groove (72) is arranged on the vehicle frame (8). The guide rail (71) is in sliding connection with the sliding groove (72).
10. A lawnmower according to claim 6, wherein, The lifting assembly comprises an electric push rod (73). The body of the electric push rod (73) is fixedly installed on the vehicle frame (8). The top end of the electric push rod (73) is connected with the frame (7).